Low voltage gaseous tube lamp and electrical circuits therefor



p 1942- P. F. LEBRUN 212947623 LOW VOLTAGE GASEOUS TUBE LAMP ANDELECTRICAL CIRCUITS THEREFOR Filed Jan. 25, 1940 3 Sheis-Sheet lATTORNEY Sept. 1, 1942. F. F. LEBRUN 2,294,623

LOW VOLTAGE GASEOUS TUBE LAMP AND ELECTRICAL CIRCUITS THEREFOR FiledJan. 25, 1940 5 Sheets-Sheet 2 ATTORNEY Sept. 1, "P LEBRUN LOW VOLTAGEGASEOUS TUBE LAMP AND ELECTRICAL CIRCUITS THEREFOR Filed Jan. 25, 1940 3Sheets-Sheet 3 /ZM MW ATTORNEY Patented Sept. 1, 1942 LOW VOLTAGEGASEOUS TUBE LAMP AND ELECTRICAL CIRCUITS THEREFOR Paul Francois Lebrun,Astoria, N. Y., assignor of one-half to Peter Synek, Astoria, N. Y.

Application January 25, 1940, Serial No. 315,489

11 Claims.

This invention relates to low voltage gaseous tub lamps and particularlyto starting devices for such lamps.

The principal object of the invention is to provide an electricallyoperated gaseous tube lamp with associated starting and operatingelectric circuits.

Another object of the invention is to provide an electric gaseous tubelamp that may be started and operated on low voltages.

A further object is to provide an electric gaseous tube lamp startingdevice operable with lamps of greater length than previously deemedpossible.

A still further object is to provide a gaseous tube lamp operable on lowvoltages and under cold climatic conditions.

A still further object is to provide a gaseous tube lighting circuitwhich is not only easy to start under cold climatic conditions but alsoeconomical during operation.

Other objects will be apparent from a consideration of thisspecification and the drawings.

Heretofore gaseous tube lamps have been restricted in theirinstallations not only as to their length but also as to the climaticconditions under which they may operate successfully. The principaldifficulty met with in the use of lamps of this type is that step upvoltage transformers are required for their operation particularly whenthe lamps are subjected to low temperatures. Extensive use of theselamps has not been made because of the diificulties of providing thehigh voltages necessary for starting them unless their lengths be short.The average length of such lamps previously in operation wasapproximately two feet for 115 volt. With the lamps and the associatedcircuits disclosed in this specification the length of lamps has beenincreased to six feet and more and their operation has been successfulunder colder climatic conditions than has heretofore been possible andonly 110 to 120 volt current has been necessary to operate them.

In th drawings:

Fig. 1 is a cross-sectional view of an electric gaseous lamp;

Fig. 2 is an enlarged view of one end of the lamp showing the mountingof a heating element and an anode in the ends of the tube;

Fig. 3 is a diagrammatic sketch of the tube and associated starting andoperating circuits;

Fig. 4 is a diagrammatic sketch of a tube and modified starting andoperating circuits;

Fig. 5 is a plan view in section of the circuit breaker in the startingcircuit;

Fig. 6 is a sectional elevation of the circuit breaker shown in Fig. 5;and

Fig. 7 is a cross-section of the circuit breaker taken on the line 1'|of Fig. 6.

The lamp consists of a glass tube l sealed at each end and in each endof which is mounted a heating filament 2 supported on wires 5, 5 thatextend through the ends of the tube and are connected to leads 6, 6. Thefilaments are made preferably of fine tungsten wires twisted together,but any other durable metal may be used. Coiled spirally around thefilaments 2 are anodes 3, 3 made preferably of some oxide coated wire.The anodes are connected to their respective filaments at only onepoint, 4, 4. Around the anodes and th filaments are mounted tubes 1, Imade of some heat conducting metal for the physical protection of thefilaments and anodes.

The tubes are exhausted of their air and are sealed under a vacuum orthey may be filled with a gas that is easily ionized. The tube iscoated, either on the inside or the outside with a fluorescent materialwhich emits light under the stimulation of the flow of current betweenthe electrodes.

Referring particularly to Figure 3, electric power is supplied by leads8, 8 through control switch 9. One side of the power leads is connectedby wire In through choke coil H to one end of the primary l2 oftransformer IS. The other side of the power leads is connected throughwire l5 to a conventional thermal circuit breaker l6 and thence to theother end of primary I2 by wire H. The secondaries M of transformer l3are connected to the heating filaments 2,2 by leads 6, 6.

Lead l9 connects one anode 3 to one power lead 8 and to one side ofcircuit breaker I6. Lead l8 connects the otheranode 3 to the other powerlead 8 through the choke coil l l and to the other end of the primary[2. This end of primary l2 could be connected to lead I0, but I preferto connect it directly to the anode 3.

Across the leads l0, I5 is connected condenser 20 and resistance 2|constituting a heating element for the circuit breaker l6, as will bedescribed later.

The starting of the tube is as follows: When switch 9 is closed,electric power is made available to transformer I3 through choke coil IIand thermal circuit breaker l6. Current also flows through condenser 20and resistance 2|. Currents from the secondaries of transformer l3 flowthrough the filaments 2, 2 and heat up the tube and gas therein. After adefinite period of time,

that is, when the tube and gas therein have become heated, the thermalcircuit breaker coil is also heated to a predetermined oper ve peratureand the circuit through the primary of the transformer I3 is broken.While the circuit is broken, high Voltage transitory currents aregenerated in the primary and are impressed upon the filaments andanodes. It is well known that when an electric circuit is broken, highvoltage transitory currents are induced, the voltage depending upon theinterval of time of the actual breaking of the circuit and theelectrical characteristics of the circuit. With the normal time oroperation of a conventional thermal-electric circuit breaker in thecircuit as described, it has been found that suflicient voltage isinduced that, when applied to the anodes, a flow of current isestablished between the anodes. Once this flow is established the linevoltage impressed on the anodes is suflicient to maintain th flow.

Resistance 2| is placed near the heating coil of circuit breaker Hi andis connected across leads I and I5. It supplies sufiicient heat to thethermal circuit breaker such that once the circuit breaker is opened, itwill be retained in its open position during the operation of the lamp.It will be noted that during the operation of the tube the only currentconsumed that is not turned directly into light is the small currentthrough the condenser and the heating resistance 2|, which is negligibleas far as a power loss is concerned as the condenser returns to itscircuit practically all of the power absorbed by it. At the same time,it will be noted, the condenser improves the power factor of the circuitas a whole.

A modification of the arrangement shown in Fig. 3 is disclosed in Fig.4. During the starting stage, one side of the power leads 3 is connectedto one side of the primary l2 of transformer 3 through conductor Ill,electromagnetic coil 24, lead l and choke coil The other side of thepower source 8 is connected to the other end of primary |2 by conductorl5, electromagnetic circuit breaker 22, hereinafter described, and leadConnected between lead l1 and one end of the choke coil iselectromagnetic coil 25 and a conventional thermal circuit maker 23.Electromagnetic coils 24 and 25 are placed in operative position nearelectromagnetic circuit breaker 22 that their fields may cause theopening of the circuit breaker and once the primary circuit is broken,the circuit breaker will remain in its open position.

The other parts of the circuit in Fig. 4 are identical with those shownin Fig. 3.

The starting of the lamp in the modified circuit is as follows: Upon theclosing of switch 9 electric power is delivered to primary l2 by leadl5, circuit breaker 22, lead l1 and lead l8, choke coil lead l0,electromagnetic coil 24 and lead Ill. The ohmic resistance of thevarious elements of this circuit are such that the currents throughcoils 24 and 25 are not enough to create a field strong enough tooperate circuit breaker 22. It will thus be seen that the heatingelements 2, 2, receive current from the secondaries l4, as previouslydescribed.

During this time, the small current through circuit maker 23 heats upits bimetal contactor arm until its contacts are closed, shortcircuiting its heating element and lowering its resistance, thuspermitting a greater current to flow through coil 25. With the circuitmaker in its closed position, the fields of coils 24 and 25 aresufreturns to its open position and no current will flow through coil25.

The circuit breaker 22 consists of a tube 3| in which is mounted a base32 made of some insulating material. On this base 32 is mounted a stiifwire 34, preferably made of tungsten or other heat resisting metal.Contact 33 is mounted at the end of wire 34. Wire 34 is secured to thebase by rivets 35 and. is connected to a lead 36 through the end of thetube.

The other contact 31 consists of an electromagnetic responsive material,.such as soft iron, and covered with a spark resisting metal such assilver or platinum. Contact 31 is supported in physical contact withcontact 33 on a spring consisting preferably of two wires 38, 39 madepreferably of some heat resisting and nonmagnetic metal such-astungsten. A sheet of other spring non-magnetic material may besubstituted for these wires. The wires 38, 39 are held in position byrivet 40 and. are connected to lead 4| which extends through the end ofthe tube 3|.

Mounted on base 32 is a second spring 43 formed as a loop and held inposition by rivet 44. This spring in its normal position, that is, whenthe contacts 33 and 31 are together, extends at an angle to the base 32and is so placed that when the spring wires 38 and 39 are deflected by amagnetic field forcing contact 31 away from contact 33, contact 31resiliently rests against spring 43. It will thus be seen that when thecircuit breaker is in its open position, any vibrations in the springs38, 39 are damped out by the spring 43 making the circuit breakernoiseless even when operating on alternating current.

A spring 45 secured by rivet 44 is in resilient contact with tube 3| tokeep one end of base 32 in position. The other end of base 32 is held inposition by the leads 36 and 4|. The tube 3| is preferably sealed undera vacuum, but it may be filled with an inert gas.

The circuit breaker is operated by an electromagnetic coil connected inthe circuit desired to be broken, the core of which coil is placed inoperative juxtaposition to the electromagnetic responsive element 31.

It is obvious that various changes may be made by those skilled in theart in the details of the embodiment of the invention shown in thedrawings and described above within the principle and scope of theinvention as expressed in the appended claims.

I claim:

1. In combination, a gaseous tube electric lamp including a. heatingelement and an anode at each end of said tube the heating elements andthe anodes being respectively connected together at one point, a chokecoil, leads connecting said anodes with a, source of electric power thesaid choke coil being connected in series in one of said leads, atransformer consisting of a primary and two secondary coils, the saidcoils being conductively separate, leads connecting the said secondariesrespectively with the said heating elements, leads connecting the saidprimary with said power, one of said leads being through the said chokecoil, and means for automatically disconnecting the other lead from saidpower after an interval of time,whereby the said heating elements heatup the said tube and whereby the high voltage transitory currentsproduced by said disconnecting are applied to said anodes.

2. In combination, a gaseous tube electric lamp including a heatingelement and an anode at each end of said tube the heating elements andthe anodes being respectively connected together at one point, leadsconnecting said anodes with a source of electric power, a transformerconsisting of a primary and two secondary coils, the

said coils being conductively separate, the primary being connectedcross said leads in shunt with the anodes, leads connecting the saidsecondaries respectively with the said heating elements,

leads connecting the said primary with said power and the said anodes,and means for breaking the said primary shunt connection, whereby thesaid heating elements heat up the said tube and whereby the high voltagetransitory currents produced by said disconnecting are applied to saidanodes.

3. In combination, a gaseous tube electric lamp including a heatingelement and an anode at each end of said tube the heating elements andthe anodes being respectively connected together at one point, a chokecoil, leads connecting said anodes with a source of electric power, thesaid choke coil being connected in series in one of said leads, atransformer consisting of a primary and two secondary coils, the saidcoils being conductively separate, the primary being connected acrosssaid leads in shunt with the anodes and between the anode and choke coilin the said one lead, leads connecting the said secondaries respectivelywith the said heating elements, means for automatically disconnectingthe said primary from said power after an interval of time, and meansfor maintaining the said disconnecting means in a disconnectedcondition.

4. In combination, a gaseous tube electric lamp including a heatingelement and an anode at each end of said tube the heating elements andthe anodes being respectively connected together at one point, a chokecoil, leads connectconnect said primary from said power after aninterval of time, and means for maintaining the circuit breaker in anopen position after it has opened its circuit.

5. In combination, a gaseous tube electric lamp including a heatingelement and an anode at each end of said tube the heating elements andthe anodes being respectively connected together at one point, a chokecoil, leads connecting said anodes with a source of electric power thesaid choke coil being connected in series in one of said leads, atransformer consisting of a primary and two secondary coils, the saidcoils being conductively separate, leads connecting the said secondariesrespectively with the said heating elements, a time delay thermalcircuit breaker, leads connecting the said primary in shunt across thefirst mentioned leads, the said circuit breaker being connected inseries in one of said last mentioned leads and operable to disconnectsaid primary from said power after an interval of time, an impedance anda heating coil, the said heating coil being mounted in juxtapositionwith said circuit breaker, and leads connecting said impedance and saidheating element in series and to said power, whereby the said circuitbreaker is held in its open position after it breaks its circuit.

6. In combination, a gaseous tube electric lamp including a heatingelement and an anode at each end of said tube the heating elements andthe anodes being respectively connected together at one point, a chokecoil, leads connecting said anodes with a source of electric power thesaid choke coil being connected in series in one of said leads, atransformer consisting of a primary and two secondary coils, the saidcoils being conductively separate, leads connecting the said secondariesrespectively with the said heating elements, a time delay thermalcircuit breaker, leads connecting the said primary in shunt across thefirst mentioned leads, the said circuit breaker being connected inseries in one of said last mentioned leads and operable to disconnectsaid primary from said power after an interval of time, a, condenser anda heating coil, the said heating coil being mounted in juxtapositionwith said circuit breaker, and leads connecting said condenser and saidheating element in series and to said power, whereby the said circuitbreaker is held in its open position after it breaks its circuit.

7. In combination, a gaseous tube electric lamp including a heatingfilament and an auxiliary anode at each end of said tube the saidfilaments and anodes being respectively connected together at one point,a choke coil, an electromagnetic circuit breaker including anelectromagnetic coil juxtaposed thereto, leads connecting said anodeswith a source of electric power, the said choke coil and the said coilbeing connected in series with each other and in series in one of saidleads, a transformer consisting of a primary and two secondary coils,the said coils being conductively separate, leads connecting saidsecondaries respectively to said filaments, a thermal delay circuitmaker, a second electromagnetic coil juxtaposed with said first coil, alead connecting one end of said primary to one contact of said circuitbreaker, a lead connecting the other contact of said circuit breaker toone of said anodes and to one side of said power, a lead connecting theother end of said primary to the other of said anodes and to one end ofsaid choke coil, and a lead including the said second coil and circuitmaker in series therewith connecting the said end of said choke coil tothe said end of said primary, whereby the action of said circuit breakeris delayed for an interval of time and upon its operation to its openposition it remains in its open position.

8. A gaseous tube electric lamp, including a heating filament and ananode at each end of said tube the heating filaments and the anodesbeing respectively connected together at one point, a transformerconsisting of a primary and two secondary coils, the said coils beingconductively separate, leads connecting said secondaries respectively tosaid filaments, a lead connecting one of said anodes to one side of asource of electric power, a power control means, an electromagneticcoil, a lead connecting the other of said means and the other end ofsaid primary adapted to augment the magnetic field of said coil to thesaid predetermined value after an interval of time.

9. A gaseous tube electric lamp, including a heating filament and ananode at each end of said tube the heating filaments and the anodesbeing respectively connected together at one point, a transformerconsisting of a primary and two secondary coils, the said coils beingconductively separate, leads connecting said secondaries respectively tosaid filaments, a lead connecting one of said anodes to one side of asource of electric power, a power control means, an electromagneticcoil, a lead connecting the other of said anodes to one end of saidprimary and to the other side of said power through successively thesaid power control means and the said coil, a second electromagneticcoil juxtaposed with first coil, an electromagnetically operated circuitbreaker juxtaposed said coils and adapted to open its contacts upon therise of the magnetic field of said coils to a predetermined value, andmeans connected to said second coil to bring the said magnetic field tothe said predetermined value after an interval of time.

10. A gaseous tube electric lamp, including a heating filament and ananode at each end of said tube the heating filaments and the anodesbeing respectively connected together at one point, a transformerconsisting of a primary and two secondary coils, the said coils beingconductively separate, leads connecting said secondaries respectively tosaid filaments, a lead connecting one of said anodes to one side of asource of electric power, a power control means, an electromagneticcoil, a lead connecting the other of said anodes to one end of saidprimary and to the other side of said power through successively thesaid power control means and the said coil, a second electromagneticcoil juxtaposed with first coil, an electromagnetically operated circuitbreaker juxtaposed said coils and adapted to open its contacts upon therise of the magnetic field of said coils to a predetermined value, and athermal delay circuit maker connected in series with said second coilacross the said primary, whereby the magnetic fields of the two coilsare brought to said predetermined value after an interval of time.

11. In combination, a gaseous tube electric lamp including a heatingfilament and an anode at each end of said tube, the heating elements andthe anodes being respectively connected together at one point, a sourceof electric power, leads connecting the anodes to opposite sides of saidsource, a transformer having a primary and two secondary coils, the saidcoils being conductively separate each secondary being connected inseries with one heating filament and the primary being connected acrossthe said leads in shunt with the electrodes, a circuit breaker in saidshunt circuit between the primary and one of said leads, and powercontrol means in the other of said leads between the shunt connectionand the power source.

PAUL FRANCOIS LEBRUN.

